I pondered this for a while before discovering that it's a mortar for mixing / grinding up something. The pestle wasn't with it.  It weights nearly 2 lbs, which is saying something as it only stands 4" tall.  It's got nice lines and I suppose could be used as a plat holder, etc.

This stands 4" tall, measures 4 1/4" across at the lip and 2 3/4" at the base.

Feel free to ask questions.  Thanks.